Topography-guided ablation for the treatment of irregular astigmatism

Kwitko, Sérgio; Cabral, Felipe P.; Araujo, Bruno Schneider de; Jung, Yuri Petermann

doi:10.1016/j.xjec.2019.04.001

Cited by 6 publications

(5 citation statements)

References 5 publications

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“…Most severe complications involve damage to the transplant or to the graft-host wound interface. These adverse outcomes were not reported for any of the eyes reviewed in this study since the diameter of the femtosecond flaps was programmed to be smaller than the diameter of the graft, avoiding the graft-host junction [33, 34].…”

Section: Discussionmentioning

confidence: 99%

Femtosecond Laser-Assisted In Situ Keratomileusis Treatment of Residual Refractive Error following Femtosecond Laser-Enabled Keratoplasty

Shen

Tsai

Castro

et al. 2019

Journal of Ophthalmology

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Purpose. To evaluate the safety and effectiveness of femtosecond laser-assisted in situ keratomileusis (LASIK) in the treatment of residual myopia and astigmatism following femtosecond laser-enabled keratoplasty (FLEK). Design. Retrospective case review. Methods. Chart review of all patients with prior FLEK who subsequently underwent femto-LASIK surgery after full suture removal was performed at the Gavin Herbert Eye Institute at the University of California, Irvine. A total of 14 eyes in 13 patients met this criterion, and their comprehensive examinations performed at standard intervals were reviewed. Main outcome measures include uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA) expressed as the logarithm of the minimum angle of resolution (logMAR), manifest refractive astigmatism, and spherical equivalent. Results. From the preoperative visit to the 3 month visit, all 14 eyes significantly improved in UDVA (logMAR, 0.93 ± 0.23 to 0.44 ± 0.32, P=0.002) with no loss of CDVA (logMAR, 0.26 ± 0.19 to 0.18 ± 0.23, P=0.50). All 14 eyes showed significant improvement in manifest refractive astigmatism (4.71 ± 1.77 to 2.18 ± 1.45 diopters (D), P=0.003) and spherical equivalent (−2.57 ± 2.45 to −0.48 ± 0.83 D, P=0.0007). There were no flap or graft complications as a result of femto-LASIK. Conclusions. Our findings suggest that femto-LASIK on eyes with prior FLEK is safe and effective in improving visual acuity and reducing residual astigmatism.

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Section: Discussionmentioning

confidence: 99%

Femtosecond Laser-Assisted In Situ Keratomileusis Treatment of Residual Refractive Error following Femtosecond Laser-Enabled Keratoplasty

Shen

Tsai

Castro

et al. 2019

Journal of Ophthalmology

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“…It has previously been demonstrated that regularization of an irregular cornea has the potential to improve best corrected visual acuity [ 26 ] and reduce undesired visual disturbances that are often associated with higher order aberrations [ 17 ]. It has also been shown that vector planning, which considers both corneal and refractive parameters, produces good visual outcomes [ 20 ], even in cornea with mild keratoconus [ 18 ].…”

Section: Discussionmentioning

confidence: 99%

“…One major feature of the method described in this paper is that the laser treatment profile is similar enough to a standard profile that the existing laser nomograms should still apply. This contrasts with generic topography-guided ablations for highly aberrated corneas, which appear to have less predictable refractive astigmatism outcomes [ 17 , 26 ]. A surgeon using the method in this paper should still be able to accurately target a specific spherocylindrical refractive outcome with a single procedure.…”

Section: Discussionmentioning

confidence: 99%

Hemidivisional vector planning to reduce and regularize irregular astigmatism by laser treatment

Alpins

Ong²,

Stamatelatos

2022

Graefes Arch Clin Exp Ophthalmol

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Purpose To demonstrate how hemidivisional vector planning of refractive laser treatments of astigmatism can be used to directly address idiopathic corneal irregular astigmatism that has an asymmetrical, non-orthogonal bow tie topography appearance. Design Case study. Methods The cornea is conceptually divided into two hemidivisions along the flat meridian of the corneal topographic astigmatism (CorT), which means that each hemidivision will approximately correspond to one lobe of the asymmetric, non-orthogonal topographic bow tie. An astigmatism reduction treatment can then be planned separately for each hemidivision using the vector planning technique, based on both its two hemidivisional CorT measures and common manifest refractive cylinder. The remaining irregularity is then regularized, and the junctional zone smoothed across the flat meridian. The final intended treatment thus combines hemidivisional astigmatism reduction and regularization of the corneal astigmatism and spherical refractive error in one treatment application. This could be applied to LASIK, PRK, SMILE, and Transepithelial PRK procedures using Designer Cornea® software. Results A theoretical treatment profile is derived from an actual example of a cornea with idiopathic asymmetric non-orthogonal astigmatism. The three steps of the derivation are as follows: (i) astigmatism reduction through the use of the vector planning technique; (ii) regularization, and (iii) smoothing across the hemidivisional midline. Conclusions Hemidivisional vector planning treatments could potentially both reduce and regularize asymmetric non-orthogonal astigmatism. These treatments can be systematically customized to account for qualitative and quantitative differences between the two corneal hemidivisions at the same time as correction of coexistent myopia or hyperopia.

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“…Treatment aims at rearranging the orientation of the astigmatism so that it is more regular and amenable to sphero-cylindrical correction. Current management options include contact lens wear such as rigid gas-permeable [ 1 ], hybrid [ 2 ] or scleral lens [ 3 ], topography-guided laser refractive surgery [ 4 ], or intrastromal corneal ring segments (ICRS) [ 5 , 6 ]. However, there are pros and cons with each of these treatments and may not be suitable for patients with poor ocular surface, those with contact lens intolerance or corneas too thin for the laser refractive surgery or ICRS to be performed safely.…”

Section: Introductionmentioning

confidence: 99%

One-year visual outcome of secondary piggyback pinhole device implantation in pseudophakic eyes with irregular corneal astigmatism and iris trauma

El‐Alfy

Hamada

et al. 2021

Eye

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Purpose Retrospective case series evaluating the efficacy and safety of implanting XtraFocus ™ pinhole device in pseudophakic patients with irregular corneal astigmatism with concurrent or standalone iris defect. Methods Electronic case records were searched for: uncorrected distance visual acuities (UDVA) and corrected distance visual acuities (CDVA), automatic or manifest refraction and spherical equivalent (SE). All main outcomes were evaluated preoperatively and postoperatively at 1, 3, 6, 9 and 12 months, along with patients’ satisfactory outcome and complications. Results Eleven pseudophakic eyes of 11 patients with a mean age of 54 (range 27–81) years were included. Median UDVA improved significantly from logMAR 0.7 (range 0.1–1.22) pre-operatively to 0.4 (range 0–1.3) at 1-month ( p = 0.002); median CDVA remained unchanged at logMAR 0.4 (range 0–0.1) pre-operatively and 0.4 (range 0–0.8) at 1-month ( p = 0.36). There were no significant statistical differences in both UDVA and CDVA between the post-operative periods. Ten patients (90.9%) had initial UDVA improvement at 1-month post op. Eight (72.7%) patients expressed satisfaction with improved vision or reduction of glare/halos. Three (27.3%) patients had unsatisfactory visual outcome resulting in 2 requested for implant explantation due to worsening of glare and distressing floaters. Conclusions XtraFocus ™ is effective in improving vision or reducing glare in pseudophakic patients with irregular corneal astigmatism or intragenic iris trauma, with over 70% expressed satisfactory outcome. Disturbing floaters and glare preclude its use in some resulting in implant explantation.

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Topography-guided ablation for the treatment of irregular astigmatism

Cited by 6 publications

References 5 publications

Femtosecond Laser-Assisted In Situ Keratomileusis Treatment of Residual Refractive Error following Femtosecond Laser-Enabled Keratoplasty

Femtosecond Laser-Assisted In Situ Keratomileusis Treatment of Residual Refractive Error following Femtosecond Laser-Enabled Keratoplasty

Hemidivisional vector planning to reduce and regularize irregular astigmatism by laser treatment

One-year visual outcome of secondary piggyback pinhole device implantation in pseudophakic eyes with irregular corneal astigmatism and iris trauma

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